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author | Tristan Gingold <tgingold@free.fr> | 2020-05-31 07:49:25 +0200 |
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committer | Tristan Gingold <tgingold@free.fr> | 2020-05-31 07:57:30 +0200 |
commit | 96a7649fe86575ca8c16aa2b46ae8d55f638b4a6 (patch) | |
tree | b4ea1e091c1a6a11c0a0b9841a453d4b63ceef5b /src/synth/netlists-inference.adb | |
parent | a785e3f228a5370d2f6550d893213a501a368cd0 (diff) | |
download | ghdl-96a7649fe86575ca8c16aa2b46ae8d55f638b4a6.tar.gz ghdl-96a7649fe86575ca8c16aa2b46ae8d55f638b4a6.tar.bz2 ghdl-96a7649fe86575ca8c16aa2b46ae8d55f638b4a6.zip |
netlists-inference: minor refactoring.
Diffstat (limited to 'src/synth/netlists-inference.adb')
-rw-r--r-- | src/synth/netlists-inference.adb | 143 |
1 files changed, 64 insertions, 79 deletions
diff --git a/src/synth/netlists-inference.adb b/src/synth/netlists-inference.adb index ed84f6127..91e095211 100644 --- a/src/synth/netlists-inference.adb +++ b/src/synth/netlists-inference.adb @@ -318,67 +318,19 @@ package body Netlists.Inference is and then Get_Input_Net (Inst, 0) = Prev_Val; end Is_Prev_FF_Value; - -- Build the FF, according to the inputs. - function Infere_FF_Create (Ctxt : Context_Acc; - Rst : Net; - Rst_Val : Net; - Init : Net; - Clk : Net; - Data : Net; - Els : Net; - Loc : Location_Type) return Net - is - Res : Net; - begin - if Rst = No_Net then - pragma Assert (Rst_Val = No_Net); - if Els = No_Net then - if Init /= No_Net then - Res := Build_Idff (Ctxt, Clk, D => Data, Init => Init); - else - Res := Build_Dff (Ctxt, Clk, D => Data); - end if; - else - if Init /= No_Net then - Res := Build_Midff (Ctxt, Clk, D => Data, - Els => Els, Init => Init); - else - Res := Build_Mdff (Ctxt, Clk, D => Data, Els => Els); - end if; - end if; - else - if Els /= No_Net then - Error_Msg_Synth - (Loc, "synchronous code does not expect else part"); - end if; - - if Init /= No_Net then - Res := Build_Iadff (Ctxt, Clk, D => Data, - Rst => Rst, Rst_Val => Rst_Val, - Init => Init); - else - Res := Build_Adff (Ctxt, Clk, D => Data, - Rst => Rst, Rst_Val => Rst_Val); - end if; - end if; - - Set_Location (Res, Loc); - - return Res; - end Infere_FF_Create; - - function Infere_FF_Else (Ctxt : Context_Acc; - Prev_Val : Net; - Off : Uns32; - Last_Mux : Instance; - Init : Net; - Rst : Net; - Rst_Val : Net; - Data : Net; - Els : Net; - Clk : Net; - Clk_Enable : Net; - Loc : Location_Type) return Net + -- Build the FF or the RAM according to the inputs. + function Infere_FF_Create (Ctxt : Context_Acc; + Prev_Val : Net; + Off : Uns32; + Last_Mux : Instance; + Init : Net; + Rst : Net; + Rst_Val : Net; + Data : Net; + Els : Net; + Clk : Net; + Clk_Enable : Net; + Loc : Location_Type) return Net is Ndata : Net; Res : Net; @@ -407,16 +359,48 @@ package body Netlists.Inference is end if; -- Create the FF. - Res := Infere_FF_Create (Ctxt, Rst, Rst_Val, - Init, Clk, Ndata, Els, Loc); + if Rst = No_Net then + pragma Assert (Rst_Val = No_Net); + if Els = No_Net then + if Init /= No_Net then + Res := Build_Idff (Ctxt, Clk, D => Ndata, Init => Init); + else + Res := Build_Dff (Ctxt, Clk, D => Ndata); + end if; + else + if Init /= No_Net then + Res := Build_Midff (Ctxt, Clk, D => Ndata, + Els => Els, Init => Init); + else + Res := Build_Mdff (Ctxt, Clk, D => Ndata, Els => Els); + end if; + end if; + else + if Els /= No_Net then + Error_Msg_Synth + (Loc, "synchronous code does not expect else part"); + end if; + + if Init /= No_Net then + Res := Build_Iadff (Ctxt, Clk, D => Ndata, + Rst => Rst, Rst_Val => Rst_Val, + Init => Init); + else + Res := Build_Adff (Ctxt, Clk, D => Ndata, + Rst => Rst, Rst_Val => Rst_Val); + end if; + end if; + + Set_Location (Res, Loc); end if; -- The output may already be used (if the target is a variable that -- is read). So redirect the net. Redirect_Inputs (Get_Output (Last_Mux, 0), Res); return Res; - end Infere_FF_Else; + end Infere_FF_Create; + -- Remove the Mux2 and handle the 'else' branch. procedure Infere_FF_Mux (Ctxt : Context_Acc; Prev_Val : Net; Off : Uns32; @@ -424,22 +408,23 @@ package body Netlists.Inference is Els : out Net; Data : out Net) is - Mux_Loc : constant Location_Type := Get_Location (Last_Mux); - Sel : constant Input := Get_Mux2_Sel (Last_Mux); - I0 : constant Input := Get_Mux2_I0 (Last_Mux); - I1 : constant Input := Get_Mux2_I1 (Last_Mux); + Mux_Loc : constant Location_Type := Get_Location (Last_Mux); + Sel : constant Input := Get_Mux2_Sel (Last_Mux); + I0 : constant Input := Get_Mux2_I0 (Last_Mux); + I1 : constant Input := Get_Mux2_I1 (Last_Mux); Els_Inst : Instance; - Els_Clk : Net; + Els_Clk : Net; Els_En : Net; - Data2 : Net; - Els2 : Net; + Els_Data : Net; + Els_Els : Net; begin - -- There must be no 'else' part for clock expression. Els := Get_Driver (I0); if Is_Prev_FF_Value (Els, Prev_Val, Off) then - -- The loop. + -- The 'else' part of the mux2 is the logical loop. Els := No_Net; else + -- The 'else' part is not a loop. It should be a second FF for a + -- DDR (not yet supported) or a true-dual-port RAM. Els_Inst := Get_Net_Parent (Els); if Get_Id (Els_Inst) = Id_Mux2 then Extract_Clock (Ctxt, Get_Driver (Get_Mux2_Sel (Els_Inst)), @@ -456,11 +441,11 @@ package body Netlists.Inference is -- 1. Remove the mux that creates the loop (will be replaced by -- the dff). - Infere_FF_Mux (Ctxt, Prev_Val, Off, Els_Inst, Els2, Data2); + Infere_FF_Mux (Ctxt, Prev_Val, Off, Els_Inst, Els_Els, Els_Data); - Els := Infere_FF_Else (Ctxt, Prev_Val, Off, Els_Inst, No_Net, - No_Net, No_Net, Data2, Els2, - Els_Clk, Els_En, Get_Location (Els_Inst)); + Els := Infere_FF_Create (Ctxt, Prev_Val, Off, Els_Inst, No_Net, + No_Net, No_Net, Els_Data, Els_Els, + Els_Clk, Els_En, Get_Location (Els_Inst)); Remove_Instance (Els_Inst); end if; end if; @@ -651,8 +636,8 @@ package body Netlists.Inference is pragma Assert (Prev_Mux = No_Instance or else Prev_Mux = Last_Mux); end; - Res := Infere_FF_Else (Ctxt, Prev_Val, Off, Last_Mux, Init, - Rst, Rst_Val, Data, Els, Clk, Enable, Mux_Loc); + Res := Infere_FF_Create (Ctxt, Prev_Val, Off, Last_Mux, Init, + Rst, Rst_Val, Data, Els, Clk, Enable, Mux_Loc); if Prev_Mux /= No_Instance then Remove_Instance (Prev_Mux); |